Bootsplash fixes from Michael Aichler <micha@aichler.net>, (comment #15
and #16 from bug #21019).
Bootsplash coded did not play nice with boot profiles, so I fixed that
as well. Some other style tweaks.

Pointed out in bug #3650 -- local VARNAME=... -- always returns 0 with
the exception of invalid variable names. The eval wasn't being checked.
Moved the 'local errstr' to its own line. (Credit: Felix von Leitner)